1. Field of the Invention
The present invention relates to a photocatalytic reaction device comprising a photocatalyst, a photocatalyst carrier that carries (or supports) this photocatalyst and a blower (an air blower), whereby substances that come into contact with, adhere to or approach the photocatalyst are decomposed by a photocatalytic reaction.
2. Description of the Related Art
Devices for cleaning air (or purifying air), comprising a dust collecting filter or deodorizing filter and a blower, are well known. An example is the device disclosed in Laid-open Japanese Patent Application No. Tokkai 2003-106581. A photocatalyst and a photocatalyst carrier that carries this photocatalyst are also known, an example being Laid-open Japanese Patent Application No. Tokkai H. 11-335187.
Photocatalytic reaction devices are also already known comprising a photocatalyst, a photocatalyst carrier made of a porous substance that carries this photocatalyst, and a blower, wherein substances coming into contact with, adhering to or approaching the photocatalyst are decomposed by a photocatalytic reaction.
A prior art of such a photocatalytic reaction device is shown in FIG. 1A and FIG. 1B. In these Figures, the lower Figure (FIG. 1B) shows a cross-sectional view including the axis (axis center) of a series of blower vanes, and the upper Figure (FIG. 1A) shows a cross-section in the direction perpendicular to the aforementioned axis, including the blower drive motor. The cross-section of the hub of the blower is not shown in the upper Figure (FIG. 1A).
In the photocatalytic reaction device 9 shown in FIG. 1A and FIG. 1B, fluid that flows in from an intake port (inlet port, suction port) 2 provided in the casing 1 flows out from a discharge port 3 arranged in the face where the intake port 2 is provided, or in a location in a face other than this. A centrifugal type blower 4 is provided, having a series of vanes 5, in the vicinity of the intake port 2 inside the casing 1 and a photocatalyst carrier 6 that carries a photocatalyst is provided at the discharge port. A blower drive motor 7 and a motor power source 8 are provided within the casing 1. In this photocatalytic reaction device 9, substances in the air coming into contact with, adhering to or approaching the catalyst carried on the photocatalyst carrier 6, such as for example impurities, are decomposed by a reaction such as oxidation or reduction.
Also, high voltage from a high-voltage power source 12 shown in these Figures is applied to high-voltage terminals 11a, 11b arranged on the upstream side and downstream side of the photocatalyst carrier 6 and electrical discharge is produced between these two terminals. Ultraviolet light is thereby generated, that promotes the decomposition action of the photocatalyst. Impurities in the air undergo oxidative decomposition by the ozone that is then generated by the ultraviolet light. Ozone that is not used in this decomposition is absorbed by an ozone decomposition filter 13 arranged on the inside of the discharge port 3.
In a prior art photocatalytic reaction device, as shown by the characteristic plot of FIG. 32, the airflow resistance of the photocatalyst carrier 6 and ozone decomposition filter 13 is R0, the external diameter of the series of vanes 5 of the centrifugal type blower 4 arranged on the internal diameter side of the photocatalyst carrier 6 is small and a partition 20 is present, so the fan performance is C0. This therefore resulted in the problem that the flow rate was small, at Q0, with the result that treatment of impurities present in the air in large quantity could not be achieved.
Also, the series of vanes 5 generates fluid noise, but, as shown in FIG. 1A and FIG. 1B, the photocatalyst carrier 6 and ozone decomposition filter 13 are arranged on the side of the discharge port 3, so noise is attenuated and the noise propagated to the outside from the discharge port 3 can thereby be reduced. However, there was the problem that noise from the intake port 2 was propagated to the outside with scarcely any attenuation.